Ecology Exam 1
Definition of Science: a system of acquiring knowledge; or, the knowledge itself
The importance of the scientific method
Media; and conflicting news/bad info
Need a basic understanding of good science; look for use of good scientific method and proper experimental design
Pseudoscience: False-Science (can not attempted to be refuted or falsified)
What do we mean by the scientific method (steps)? (hypothetico-deductive method)
Observation
Be curious; notice small details, be precise
Gather information
Synthesize relevant info.; includes peer reviewed articles and know info
Hypothesis testing
Hyp Ha: A tentative statement about nature, the purpose of which is to suggest experiments (a ‘best guess’) Null Hyp H0: There is no significant relationship between observation and hyp
Prediction
Take the null and put it as a if then statement; but be specific
Experiment
A well thought out prediction should suggest the proper experiment with it being replicated with guide lines
Conclusion
Descriptive stamtents that best explain the results; compair your studies to other similar studies; if results are inline with previous existing theories in increases our confidence
Communication of results
Should report even if you fail to reject the null; you cant get stuck on one hypothesis if its not working
Observational vs. Manipulative Experiments
Obervational (Natural): Take advantage of natural events or natural differences
Manipulative Experiment: higher power to detect differences, more control, more costly; you remove a top predator or mimic a natural occurring event in a lab or field
Publication Process
Maniscrpit order
Abstract
Intro
Methods
Results
Discussions
Conclusions
Literature Cited
Submit this work to one journal and one journal only; this helps the publisher save time and not have a double publish and how we can catch bad science with the publisher having this peer reviewed and looked at
Other Scientific methods
Descriptive Science
Observational methods oldest
Explanations may come from myth, religion
No testable hypothesis
Induction
Similar to descriptive science in that there are no hypotheses
Data is subject to analysis but usually no correlation analysis
Correlation does NOT equal causation
Once a theory has been tested repeatedly it can be a law or a principle
Theory of Evolution
Elements of a Good Experimental Design
Control
An treatment against which one or more other treatments can be compared.
Identical except does not receive the manipulation under investigation
Replication (Sample SIze)
Replication is having more than one experimental unit PER Treatment
Sample size = # of experimental units per treatment (Tanks of fish)
Greater replication: closer to true average, greater power to detect differences
Randomization
Process of randomly allocating treatments and controls to experimental units
OR randomly selecting samples from the population of interest
Bias
Bias is a systematic error
A balance of a scale is always 24g heavy
May involve favoring
Sampling streams at road crossings
Picking out the easiest to catch mice
Can be skewed by personal beliefs, culture, or religious beliefs
Example of Bias: Craniometry
Popular in mid-1800s
Ranking people on intelligence by volume of skull
Knew which skulls belonged to who did not account for sex and other factors
Quasi-Experiments (one or more key components missing)
Money
Logistics; rare animals, transportation issues
Ethical problems; what is it going to do to humans or animals
The independent variable is not manipulated by the researcher
Treatment and control groups might not be randomized
May lack a true control
Result of a Quasi-Experiment: Researcher is limited in what he/she can say
Types of Variables
Dependent Variable: What is measured. Response variable. End point. Effect
Independent Variable: This is what is manipulated; or the effects of which you wish to determine
Confounding Variable: A variable other than your independent variable, that effects your dependent variable
To see an experiment example look at PowerPoint slides from 2/1
Individuals
Interactions with their environments: temp, water, nutrients, energy
Interaction with each other (social): Mating, protection. etc.
Temperature and what effects it
Microclimates (small-scale weather variation measured in a shorter time period) interact with the local landscape to produce microclimatic variation
Altitudes can affect micro climates severely
Aspect (North vs South, valleys, mountains)
Vegetation (leaf covers in jungles)
Ground Colors (color of sands or soil)
Boulders/burrows/caves (create shadows, and cool temperature
MISSED CLASS 02/03/23
Thermal Zones and Ecto/homeo-therms
Ectotherms rely mainly on external factors for body temps
Endotherms heavily relay on internal energy for body temp regulation
A homeotherm has a higher energy output, but can only function over a narrow range of body temperatures
Thermal neutral zone: range of environmental temps. Over which the metabolic rate of a homeothermic animal does not change
Every species has its own thermal neutral zone in which it can function, this is a product of where they reside, arctic species can survive a large range of temperatures for example
Homeostasis requires energy (work)
Homeostasis can be costly if it involves maintaining body temp when the environmental temp outside the thermal neutral zone
Adaptations by aquatic animals for low tempatures
Air breathing
Fat or blubber
Fur
Counter-current heat exchange
Conductive heat loss to water is 20-100x more rapid then air
This is why otters have fur, it creates little air pockets between the fur and skin and
Counter current heat exchange In aquatic mammals vs fish
Mammals (dolphins)
The stuff furthest away from the heart starts to get colder first
Blood moves in opposite directions arteries away from the heart (warm blood) veins move blood to the heart (Cold blood)
With the current moving in the opposite directions it creates a heat exchange
Tuna (cold blooded fish)
Oxygen and cold water moves through the gills
The viens transport warm blood to the muscles for energy and the artires carry cold blood to the heart creating counter current exchange
Many organisms survive extreme temperatures by entering a resting stage
Inactivity
Seek shelter during extreme temperatures, or just stop moving
Reducing metabolic rate
Torpor: Lower metabolic rate and body temp for a short period of time (Can reduce metabolic rate sigficatly usually just over night tho)
Hibernation: reduced metabolic rate for months in the winter (cold temps)
Estivation: Reduced metabolic rate for months in the summer (warm temps)
UNIT Individual-Level Ecology
Behavioral Ecology
Study of social relations
Interactions between organisms and the enviroment, mediated by behavior
Asexual Reproduction
Only one parent; no meiosis, no fertilization
Bacteria, some fungi, some plants, stargish, waterfleas
Less energy required compared to reg. Mating
Rapid colonization and more offspring
One major flaw in asexual reproduction is the lack of genetic diversity
Sexual Reproduction
Fusion of distinct male and females gametes to produce a zygote
Mammals, birds, some plants, many inverts
Advantages: genetic diversity
Disadvantages: Costly (production of flowers, gonads, elaborate displays)
Female and males are limited by different things sexually. Females would be resources access and males would be mate access, females produce larger more energy-consuming eggs while males produce small gametes and are less energy-consuming
Some species’ sex is determined in the womb or egg (aligators)
Sex is determined by temperatures
<86F→ All females
93F → All males
In between → Mix
This would be a frequency-dependent selection
Some organisms are hermaphrodites
Sequential: starts out one sex, then converts
Mate choice, or competition for mates, can result in selection for particular traits
Sexual selection
Fitness: the number of viable offspring contributed by an individual to future generations
Off spring must reproduce to count as viable
Sexual selection: Differences in reproductive rates among individuals through differences in mating success.
Intrasexual selection: individuals of the smae sex fighting over a mate (competing)
Intersexual selection: one sex chooses mates (opposite sex) based on particualar traits
Evolution of socialaty may be accompanied by cooperative feeding, DEFENSE OF THE GROUP, AND RESTRICTED REPRODUCTIVE OPPEORTUNITES
Cooperative breeders
Members of groups may have reduced mating opportunities
Non-breeders cooperate in rearing others others’ offspring
Not altruistic
Helpers benefit still
Kin selection: related, so still passing on some alleles
Improed chance of own reproduction: inherit territory; recruit helpers themselves; learn parenting skills
Kin selection appears to play a key role in the evolution of eusociality
Eusocilaity: more complex, higher level sociality (Colonies of ants, wasps, bees, termites)
Major characteristics of eusociality
More than one generation
Cooperative care
Non-reproductive and reproductive castes
Castes: groups of physically distinct members with different roles
Cates systems and Eusociality
Caste: groups of physically distinct members with different roles
Leafcutter ants have to largest caste system with 29 different castes
Organisms with caste systems: Bees, ants, wasps, termites
Haplodiploidy in honey bees
Males developed from unfertilized eggs and are haploid (only one allel F)
Females are developed from fertilized eggs and are diploid (two allele M and F)
Queen can choose wether the egg she lays in fertlized or not creating males and females
Evolutionary, it is better for a daughter to help rear he sisters because they are 75% related
Queens are fed royal jelly throught the larval stage (16 days), while normal workers are feed royal jelly for 2 days in the larval stage
Different development, although they have the same genetics
Thye have different expression of genes, but this is regulated through nutrition in larval stage
Queen put out pheromones to chemically suppress other females in the colony
Population Genetics
Population genetics: is important in the study of: Evolution, conservation ecology, ecotoxicology
Evolution was credited to Darwin and Mendel
Darwin: wrote the Origin of species by means of Natural Selection (1859)
Focused other scientists on the diversity of organisms
Evolution: Descent with modification
Took a 5 year journey on the HMS Beagle collecting 1000’s of specimens aroccs the world
Intruged with the organisms on the Galagos islands; species found here were different then others nearby but still simmilar
Wallace: also had the same ideas as darwin at the same time
Colaborated with wallace
Wallace wrote papers later defending darwin but continued to work to be a biogeographer
Lecture Online
Darwins proposed mechanism for adaptation, or evolucion, is natural selection
Natural selection: organisms can change over generations if individuals with certain hertiable traits leave more offspring than others
Two key observations of Natural selection: over production and variance
Overproduction makes it hard for offspring to survive creating good offspring to reproduce, individuals with with best suited traits will leave more viable offspring
Variation: exists among individuals in a population, much of this variation is heritable
Mendel worked on peas which showed great inhearidence and were predictable
Phenotypic variation among indiviuals in a population results from combined effects of genes (specif alles) in the environment
An organims genetic makeup (specific alleles). Usually refers to a particular trait (PP, Pp, pp)
Phenotype: physical expression of the interaction between genotype and environment.
Isolated populations are more likely to diverge into a sub-species or a totally new species
Evolution: changes in allele frequencies over time
The hardy-Weinburg equilibrium model helps identify evolutionary forces over time (changes in alleles)
In a pop. mating at random in the abstinence of evolutionary forces alleles will remain constant
How to be in HWB equilerbruim
No mutations
Large (n)
No migration
Random mating
No natural selection (no advantages in alleles)
Likely one of these conditions will be meet; leading to not be in HWB
Agents of change
Mutation
Genetic drift
migration/gene flow
Natural selection
Mutation
Random changes in DNA molecules; Can be inherited by offspring of occur in gametes
Source of all genetic vartion
No effect, detrimental, beneficial
Benefical → natural selection, adaptation
All different kinds of mutations
Substituation (or replacement) of nucleotide
Insertion of nucleotide (everything after that insertion is changed)
Deletion of a nucleotide (Everything after that is changed)
Genetic Drift
Can change gene frequenecies; especially in small populations
Changes due to chance alone (random)
Bottle neck
Drastic reduction in pop. size
By chance, certain alleles may be over or under represented among survivors; usually reduces gentetic diverstiy
Habitiat fragmentation and overhunting can cause the bottle neck
Founders effect
Genetic drift in a new colony
Founder population has different allele frequenscies than source pop. (by random chance)
Migration
Transfer of alleles into or out of a pop. (Random)
Movement of individuals among populations
Immigration
Emmigration
Increase or decrease of genetic diversity
Natural Selection (Not Random; Adaptive)
Of all causes of evolution, only natural selection is adaptive
Random generation of genetic variability leads to differential reproductive success (better fit)
Development of pesticide resistance
Insecticide only kills off the ones who it works on; leaving the bugs left over to breed with those alleles which are suited for it
Natural selection is the result of differences in survival and reproduction among phenotypes
Discussion of paper
Advatages of BACI design: Allows you to take into account;
Differences among sites at the start.
Environmental changes over time
Definition of Science: a system of acquiring knowledge; or, the knowledge itself
The importance of the scientific method
Media; and conflicting news/bad info
Need a basic understanding of good science; look for use of good scientific method and proper experimental design
Pseudoscience: False-Science (can not attempted to be refuted or falsified)
What do we mean by the scientific method (steps)? (hypothetico-deductive method)
Observation
Be curious; notice small details, be precise
Gather information
Synthesize relevant info.; includes peer reviewed articles and know info
Hypothesis testing
Hyp Ha: A tentative statement about nature, the purpose of which is to suggest experiments (a ‘best guess’) Null Hyp H0: There is no significant relationship between observation and hyp
Prediction
Take the null and put it as a if then statement; but be specific
Experiment
A well thought out prediction should suggest the proper experiment with it being replicated with guide lines
Conclusion
Descriptive stamtents that best explain the results; compair your studies to other similar studies; if results are inline with previous existing theories in increases our confidence
Communication of results
Should report even if you fail to reject the null; you cant get stuck on one hypothesis if its not working
Observational vs. Manipulative Experiments
Obervational (Natural): Take advantage of natural events or natural differences
Manipulative Experiment: higher power to detect differences, more control, more costly; you remove a top predator or mimic a natural occurring event in a lab or field
Publication Process
Maniscrpit order
Abstract
Intro
Methods
Results
Discussions
Conclusions
Literature Cited
Submit this work to one journal and one journal only; this helps the publisher save time and not have a double publish and how we can catch bad science with the publisher having this peer reviewed and looked at
Other Scientific methods
Descriptive Science
Observational methods oldest
Explanations may come from myth, religion
No testable hypothesis
Induction
Similar to descriptive science in that there are no hypotheses
Data is subject to analysis but usually no correlation analysis
Correlation does NOT equal causation
Once a theory has been tested repeatedly it can be a law or a principle
Theory of Evolution
Elements of a Good Experimental Design
Control
An treatment against which one or more other treatments can be compared.
Identical except does not receive the manipulation under investigation
Replication (Sample SIze)
Replication is having more than one experimental unit PER Treatment
Sample size = # of experimental units per treatment (Tanks of fish)
Greater replication: closer to true average, greater power to detect differences
Randomization
Process of randomly allocating treatments and controls to experimental units
OR randomly selecting samples from the population of interest
Bias
Bias is a systematic error
A balance of a scale is always 24g heavy
May involve favoring
Sampling streams at road crossings
Picking out the easiest to catch mice
Can be skewed by personal beliefs, culture, or religious beliefs
Example of Bias: Craniometry
Popular in mid-1800s
Ranking people on intelligence by volume of skull
Knew which skulls belonged to who did not account for sex and other factors
Quasi-Experiments (one or more key components missing)
Money
Logistics; rare animals, transportation issues
Ethical problems; what is it going to do to humans or animals
The independent variable is not manipulated by the researcher
Treatment and control groups might not be randomized
May lack a true control
Result of a Quasi-Experiment: Researcher is limited in what he/she can say
Types of Variables
Dependent Variable: What is measured. Response variable. End point. Effect
Independent Variable: This is what is manipulated; or the effects of which you wish to determine
Confounding Variable: A variable other than your independent variable, that effects your dependent variable
To see an experiment example look at PowerPoint slides from 2/1
Individuals
Interactions with their environments: temp, water, nutrients, energy
Interaction with each other (social): Mating, protection. etc.
Temperature and what effects it
Microclimates (small-scale weather variation measured in a shorter time period) interact with the local landscape to produce microclimatic variation
Altitudes can affect micro climates severely
Aspect (North vs South, valleys, mountains)
Vegetation (leaf covers in jungles)
Ground Colors (color of sands or soil)
Boulders/burrows/caves (create shadows, and cool temperature
MISSED CLASS 02/03/23
Thermal Zones and Ecto/homeo-therms
Ectotherms rely mainly on external factors for body temps
Endotherms heavily relay on internal energy for body temp regulation
A homeotherm has a higher energy output, but can only function over a narrow range of body temperatures
Thermal neutral zone: range of environmental temps. Over which the metabolic rate of a homeothermic animal does not change
Every species has its own thermal neutral zone in which it can function, this is a product of where they reside, arctic species can survive a large range of temperatures for example
Homeostasis requires energy (work)
Homeostasis can be costly if it involves maintaining body temp when the environmental temp outside the thermal neutral zone
Adaptations by aquatic animals for low tempatures
Air breathing
Fat or blubber
Fur
Counter-current heat exchange
Conductive heat loss to water is 20-100x more rapid then air
This is why otters have fur, it creates little air pockets between the fur and skin and
Counter current heat exchange In aquatic mammals vs fish
Mammals (dolphins)
The stuff furthest away from the heart starts to get colder first
Blood moves in opposite directions arteries away from the heart (warm blood) veins move blood to the heart (Cold blood)
With the current moving in the opposite directions it creates a heat exchange
Tuna (cold blooded fish)
Oxygen and cold water moves through the gills
The viens transport warm blood to the muscles for energy and the artires carry cold blood to the heart creating counter current exchange
Many organisms survive extreme temperatures by entering a resting stage
Inactivity
Seek shelter during extreme temperatures, or just stop moving
Reducing metabolic rate
Torpor: Lower metabolic rate and body temp for a short period of time (Can reduce metabolic rate sigficatly usually just over night tho)
Hibernation: reduced metabolic rate for months in the winter (cold temps)
Estivation: Reduced metabolic rate for months in the summer (warm temps)
UNIT Individual-Level Ecology
Behavioral Ecology
Study of social relations
Interactions between organisms and the enviroment, mediated by behavior
Asexual Reproduction
Only one parent; no meiosis, no fertilization
Bacteria, some fungi, some plants, stargish, waterfleas
Less energy required compared to reg. Mating
Rapid colonization and more offspring
One major flaw in asexual reproduction is the lack of genetic diversity
Sexual Reproduction
Fusion of distinct male and females gametes to produce a zygote
Mammals, birds, some plants, many inverts
Advantages: genetic diversity
Disadvantages: Costly (production of flowers, gonads, elaborate displays)
Female and males are limited by different things sexually. Females would be resources access and males would be mate access, females produce larger more energy-consuming eggs while males produce small gametes and are less energy-consuming
Some species’ sex is determined in the womb or egg (aligators)
Sex is determined by temperatures
<86F→ All females
93F → All males
In between → Mix
This would be a frequency-dependent selection
Some organisms are hermaphrodites
Sequential: starts out one sex, then converts
Mate choice, or competition for mates, can result in selection for particular traits
Sexual selection
Fitness: the number of viable offspring contributed by an individual to future generations
Off spring must reproduce to count as viable
Sexual selection: Differences in reproductive rates among individuals through differences in mating success.
Intrasexual selection: individuals of the smae sex fighting over a mate (competing)
Intersexual selection: one sex chooses mates (opposite sex) based on particualar traits
Evolution of socialaty may be accompanied by cooperative feeding, DEFENSE OF THE GROUP, AND RESTRICTED REPRODUCTIVE OPPEORTUNITES
Cooperative breeders
Members of groups may have reduced mating opportunities
Non-breeders cooperate in rearing others others’ offspring
Not altruistic
Helpers benefit still
Kin selection: related, so still passing on some alleles
Improed chance of own reproduction: inherit territory; recruit helpers themselves; learn parenting skills
Kin selection appears to play a key role in the evolution of eusociality
Eusocilaity: more complex, higher level sociality (Colonies of ants, wasps, bees, termites)
Major characteristics of eusociality
More than one generation
Cooperative care
Non-reproductive and reproductive castes
Castes: groups of physically distinct members with different roles
Cates systems and Eusociality
Caste: groups of physically distinct members with different roles
Leafcutter ants have to largest caste system with 29 different castes
Organisms with caste systems: Bees, ants, wasps, termites
Haplodiploidy in honey bees
Males developed from unfertilized eggs and are haploid (only one allel F)
Females are developed from fertilized eggs and are diploid (two allele M and F)
Queen can choose wether the egg she lays in fertlized or not creating males and females
Evolutionary, it is better for a daughter to help rear he sisters because they are 75% related
Queens are fed royal jelly throught the larval stage (16 days), while normal workers are feed royal jelly for 2 days in the larval stage
Different development, although they have the same genetics
Thye have different expression of genes, but this is regulated through nutrition in larval stage
Queen put out pheromones to chemically suppress other females in the colony
Population Genetics
Population genetics: is important in the study of: Evolution, conservation ecology, ecotoxicology
Evolution was credited to Darwin and Mendel
Darwin: wrote the Origin of species by means of Natural Selection (1859)
Focused other scientists on the diversity of organisms
Evolution: Descent with modification
Took a 5 year journey on the HMS Beagle collecting 1000’s of specimens aroccs the world
Intruged with the organisms on the Galagos islands; species found here were different then others nearby but still simmilar
Wallace: also had the same ideas as darwin at the same time
Colaborated with wallace
Wallace wrote papers later defending darwin but continued to work to be a biogeographer
Lecture Online
Darwins proposed mechanism for adaptation, or evolucion, is natural selection
Natural selection: organisms can change over generations if individuals with certain hertiable traits leave more offspring than others
Two key observations of Natural selection: over production and variance
Overproduction makes it hard for offspring to survive creating good offspring to reproduce, individuals with with best suited traits will leave more viable offspring
Variation: exists among individuals in a population, much of this variation is heritable
Mendel worked on peas which showed great inhearidence and were predictable
Phenotypic variation among indiviuals in a population results from combined effects of genes (specif alles) in the environment
An organims genetic makeup (specific alleles). Usually refers to a particular trait (PP, Pp, pp)
Phenotype: physical expression of the interaction between genotype and environment.
Isolated populations are more likely to diverge into a sub-species or a totally new species
Evolution: changes in allele frequencies over time
The hardy-Weinburg equilibrium model helps identify evolutionary forces over time (changes in alleles)
In a pop. mating at random in the abstinence of evolutionary forces alleles will remain constant
How to be in HWB equilerbruim
No mutations
Large (n)
No migration
Random mating
No natural selection (no advantages in alleles)
Likely one of these conditions will be meet; leading to not be in HWB
Agents of change
Mutation
Genetic drift
migration/gene flow
Natural selection
Mutation
Random changes in DNA molecules; Can be inherited by offspring of occur in gametes
Source of all genetic vartion
No effect, detrimental, beneficial
Benefical → natural selection, adaptation
All different kinds of mutations
Substituation (or replacement) of nucleotide
Insertion of nucleotide (everything after that insertion is changed)
Deletion of a nucleotide (Everything after that is changed)
Genetic Drift
Can change gene frequenecies; especially in small populations
Changes due to chance alone (random)
Bottle neck
Drastic reduction in pop. size
By chance, certain alleles may be over or under represented among survivors; usually reduces gentetic diverstiy
Habitiat fragmentation and overhunting can cause the bottle neck
Founders effect
Genetic drift in a new colony
Founder population has different allele frequenscies than source pop. (by random chance)
Migration
Transfer of alleles into or out of a pop. (Random)
Movement of individuals among populations
Immigration
Emmigration
Increase or decrease of genetic diversity
Natural Selection (Not Random; Adaptive)
Of all causes of evolution, only natural selection is adaptive
Random generation of genetic variability leads to differential reproductive success (better fit)
Development of pesticide resistance
Insecticide only kills off the ones who it works on; leaving the bugs left over to breed with those alleles which are suited for it
Natural selection is the result of differences in survival and reproduction among phenotypes
Discussion of paper
Advatages of BACI design: Allows you to take into account;
Differences among sites at the start.
Environmental changes over time